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I got this GK 800rb for $30. Wouldn't power on. It's taken me a couple days to figure out what was up but I finally fixed it so I'm super stoked on this. Now it's time to find a good cabinet to use with it. The seller included the original transformer which was shot and there was a new one in there.

FYI if anyone ends up having an issue with their's in the future, the issue was that all the transistors that are screwed/attached to a grounding plate were loose - all the screws were loose and weren't providing a good ground connection.

I also recommend building a simple light bulb limiter. I've worked on tube amps before and feel stupid I never used one before. It's a good safety precaution and let's you know if their are shorts that might otherwise damage the equipment.

awesome!

Faldoe wrote:I got this GK 800rb for $30. Wouldn't power on. It's taken me a couple days to figure out what was up but I finally fixed it so I'm super stoked on this. Now it's time to find a good cabinet to use with it. The seller included the original transformer which was shot and there was a new one in there.

FYI if anyone ends up having an issue with their's in the future, the issue was that all the transistors that are screwed/attached to a grounding plate were loose - all the screws were loose and weren't providing a good ground connection.

so you literally had to tighten 4 screws?

yep, so much win. the rbs have a cool modern solidstaty sound

JonnyAngle wrote:

Faldoe wrote:I got this GK 800rb for $30. Wouldn't power on. It's taken me a couple days to figure out what was up but I finally fixed it so I'm super stoked on this. Now it's time to find a good cabinet to use with it. The seller included the original transformer which was shot and there was a new one in there.

FYI if anyone ends up having an issue with their's in the future, the issue was that all the transistors that are screwed/attached to a grounding plate were loose - all the screws were loose and weren't providing a good ground connection.

so you literally had to tighten 4 screws?

Well I had to do a bunch of tests to rule out issues but once I noticed some were loose I tightened every component that had a chassis grounding/anchored screw.

I first pulled the transformer and tested it, then attached it to the power supply board and disconnected the PSB from the Power Amp board and tested the transformer to the PSB, which tested ok and that's when I started to poke around the PAB.